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To: Tig <tigger@onemoremonkey.com>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Fri, 20 Aug 2004 00:48:43 +1000."
             <20040820004843.011b8de8@piglet.goo> 
Date: Thu, 19 Aug 2004 16:53:53 +0200
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cc: freebsd-security@freebsd.org
Subject: Re: Report of collision-generation with MD5 
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In message <20040820004843.011b8de8@piglet.goo>, Tig writes:
>On Wed, 18 Aug 2004 14:29:57 -0400
>"Peter C. Lai" <sirmoo@cowbert.net> wrote:
>
>> On Wed, Aug 18, 2004 at 09:08:12PM +0300, Claudiu wrote:
>> > hello,
>> > 
>> > please explain what do you mean by "reverse the hash". Is this the 
>> > recreation of the originial message from its hash ?
>> 
>> The short answer is yes. The slightly longer answer is that such is
>> only one specific case. The general case is that the digest should not
>> reveal any information about the original message.
>> 
>
>
>If this is the case, then it would be very cool!
>
>Imagine sending 32 bytes, then 'reverse the hash' to get XX MB's worth
>of data :]
>
>That would be great compression!

That would not be compression (and hopefully you know it).

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.